1. Field of the Invention
The present invention relates to a knee protecting airbag device, in which an airbag to be expanded and inflated by admitting an inflating gas can protect the knees of a passenger such as a driver or a person seated on the passenger's seat.
2. Description of the Related Art
In the prior art, a device for protecting the knees of a passenger such as a driver is disclosed in Unexamined Published Japanese Patent Application No. 31589/1998. This airbag device includes: an airbag folded in an expandable and inflatable manner in front of the knees of the seated passenger; an inflator for feeding an inflating gas to the airbag; and a case for housing and holding the folded airbag and the inflator. Moreover, the inflator is housed in a portion of the airbag that is held in the case when the airbag is completely expanded and inflated.
When this device is active, the airbag is protruded to the rear of the vehicle from the case when fed with the inflating gas, so that it can be expanded and inflated to protect the knees of the passenger.
From the viewpoint of assembling workability, moreover, the knee protecting airbag device preferably comprises an airbag, inflator and case which form one assembly and are integrated before being mounted on the vehicle.
However, the airbag device of this publication is not clear regarding the structure of the lead wires for inputting an activation signal from an airbag activation circuit mounted on the vehicle to the inflator. Therefore, this airbag device can be improved if activation signal inputting lead wires are smoothly connected with the inflator after the airbag and the inflator were housed in the case.
Another device for protecting the knees of the passenger such as the driver is disclosed in WO 02/04262. This airbag device is arranged on the lower side of the column cover below the steering wheel. When activated, moreover, the airbag is expanded and inflated upward from the lower side of the column cover below the steering wheel so that the knees of the driver may be protected by the airbag when inflated.
In the airbag device thus constructed, the airbag is folded and housed in the case whose side facing the rear of the vehicle has been opened. And, the airbag is protruded to the rear of the vehicle from the opening of the case and is expanded upward while being unfolded, to complete its inflation.
In connection with the behavior of the airbag to be protruded from the case to complete its inflation, the airbag is desirably expanded upward while suppressing its protrusion to the passenger. Especially in case the case has its axial direction approximating the horizontal direction, the airbag is liable to be excessively protruded to the passenger. This is because the airbag is protruded along the axis of the case.